Abstract: I will discuss electron transport through a double quantum dot system coupled to a microwave resonator. First, I analyze the photovoltaic current produced at zero bias across the dots in the presence of microwave drive of the resonator. The conversion of photons to electronic excitations produces an electric current. I show that certain features of this current are due to quantum nature of the electromagnetic field in the resonator. In particular, the photovoltaic current exhibits a double peak dependence on the frequency of an external microwave source.

The distance between the peaks is determined by the strength of interaction between a single photon in the resonator and electrons in the double quantum dot. This double peak feature disappears as strengths of energy and phase relaxation processes increases, recovering a simple classical condition for maximal current when the energy splitting between electronic states in the double quantum dot is equal to the photon energy. Then I discuss properties of electric current and photon field at finite bias across the DQD system and at zero microwave drive. I show that the low frequency current noise is affected by the coupling to photons and that the generated microwave field of the resonator may exhibit either photon bunching or antibunching.